Bret 944

Symptoms on 1988 N/A:

Temperature rises fairly quickly when idling, but it goes back down whenever I rev the engine. If I keep the enging at a constant speed of about 2000rpms, instead of idle, the engine stays cool. Does not get hot while driving (needle sits about in the middle of the gauge) down the road.

I tried a search but could not find a definitive answer.

TIA
Bret

EZRider

Sounds like a bad water pump belt or the pump itself.

Bret 944

Could the belt be slipping on the pump, I think it's about time for a retension anyway?

Techno Duck

If the belt is slipping on the pump, that means your timing belt is very loose, which could be dangerous to your vavles and wallet. When was the last time you changed the water pump or do you have any idea how many miles are on it? Take the cam cover off and check for play in the waterpump roller/bearing.

When going through the trouble to change the H2O pump, it may be worth going the "While im in there" path. Change all the belts, rollers, thermostat and maybe even do the front seals if you have the time. You may need to upgrade to the newer style waterpump also, requires minor work to make fitment (cutting of the rear cam cover, no big deal). Also one of the idler rollers is a little larger. The new pumps come with a belt 'brush' guard which prevents the belt from coming in contact with itself.

Bret 944

Belts/WP/Rollers were done by me (well, I paid at least) mid last year. Normal retension was done shortly after, but they haven't been touched since. I may just need to retension.